Apple released iOS 8 beta to the developers. Maybe you have installed it, but found it too buggy that you can’t stand. Then You want to go back to iOS 7.1.1. Actually, downgrading from iOS 8 to iOS 7 is quite easy. Just follow these instructions.
You will lose all your data
Before beginning, you need to know that you will lose all your data from iOS 8 and you can not restore your device from an iOS 8 backup on iOS 7. That means if you only have an iOS 8 backup, you can’t use it to restore your device after downgrading. But if you have an older iCloud or iTunes backup from iOS 7, you will be able to restore to it. So please make sure you have backed up your important data with iTunes or iCloud.
How to downgrade iOS 8 beta to iOS 7.1.1
1. Download the properiOS 7.1.1 IPSW firmware file for your device here.
2. Connect your device to your computer and launch the latest version of iTunes.
3 Hold down the Shift key (on Windows) and click the Restore button, while Mac users hold down Alt or Option key.
4. Browse and select the iOS 7.1.1 IPSW firmware file you downloaded earlier and click ‘Open’ button.
5. Your device will now restore to iOS 7.1.1. The restore process may take about 10-15 minutes. Once completed, your device will be downgraded from iOS 8 beta to iOS 7.
6. If you have an iOS 7 backup, you can now restore your device from it.
1. Apple has closed the signing window for any firmware below iOS 7.1.1. So it is impossible to go back to iOS 7.0.6 or below, only iOS 7.1.1.
2. If you are jailbroken and upgrade to iOS 8 beta, you will lose your jailbreak. If you want to jailbreak after downgrading, you may want to read these: How to jailbreak iOS 7.1.1 with Pangu on Windows or Mac.